Lab Analysis
Absorbtivity is a proportionality constant dependent on: A.molecular properties of species, B.Wavelength, C.Chemical Environment, or D.All of the above?
D. All of the Above
what is the most common instrument used for sugar concentration measurement in solution?
refractometer
Which title and part of the Code of Federal Regulations is Good Manufacturing Practices found?
Title 21, Part 110
A characteristic of an emetic form is that it causes nausea but not
Diarrhea
Organic acids have inhibitory effect against bacteria in certain conditions. These acids enter the bacterial cell and dissociate to form hydrogen ions, which reduce the ______________ force leading to cell destruction.
Proton Motive Force
In chromatography, what is the ratio of the distance moved by a component divided by the distance moved by the solvent?
Relative mobility
TBA test is commonly used for testing degree of rancidity of meat or fish product. What does TBA stand for?
Thiobarbituric acid Test
What is defined as "the careful consideration of all available pest control techniques and subsequent integration of appropriate measures that discourage the development of pest populations and keep pesticides and other interventions to appropriate levels"?
integrated pest management
For what reason are raspberries dipped in acid or vinegar?
norovirus
Fruits and vegetable may contain an enzyme which degrade hydroperoxides to volatile C6 and C4 aldehydes. What are these enzymes called?
Hydroperoxide lyases
The theory of spectrophotometry is based on what formula? state the meaning of each symbol in the formula
A=ECL (Beer-Lambert Law). A is absorption, E is Molar Extinction Coefficient, C is concentration in moles/L, L is the length of the light path in cm
2,6-dichlorophenol-indophenol is used to determine the content of what in fruit and fruit juices?
vitamin c
Honest and informative labeling is required by law through which act enforced by what federal agency
Fair Packaging and Labelling Act, enforced by FDA
Name 2 toxins in cassava
linamarin + lotrautlin
Cloud stability in products like tomato and orange juice is favored by the inactivation of what enzyme?
Inactivation of PME
Describe the difference between in vivo, in vitro, and ex vivo studies.
In vivo: studied in a living organism, in vitro: studied in culture, ex vivo: cells from a living organism studied in culture
Give 3 examples where enzymes are measured as an indication of quality or as a processing efficiency check.
Lipoxygenase=blanching; peroxidase=blanching; phosphatase=milk pasteurization; alpha-amylase=starch quality; rennet=curd production efficiency
According to the FD&C Act and the FPLA, what 4 items of information are required on a food label?
name and address of manufacturer, amount of food in package, common name of the food, and the ingredients of the food
Symptoms from this organism (genus and ssp) are often mis-diagnosed as appendicitis, and have resulted in many unnecessary appendectomies
Yersinnia enterocolitica
what bond does lysozyme hydrolyze?
the beta 1-4 glycosydic bonds between N acetymuramic acid (NAMA) and N acetyl glucoseamine (NAGA) in gram positive bacteria peptidoglycan layer of the cell wall
Define the following terms used to describe peaks on an MS Spectrum: 1) Base peak (base ion). 2) Molecular ion (parent ion).
1) Base peak (base ion): Fragment with the highest abundance. 2) Molecular ion (parent ion): Highest mass to charge ratio value, presents the analyte with a positive charge.
Describe the Babcock method
Add a specific volume of milk and H2SO4 to babcock bottle, the sulphuric acid digests the protein and releases fat. On centrifugation the fat rises to the top. Read the faton% calibrated neck of babcok bottle.
What California proposition revamps the labeling of compounds that are known to cause cancer or that are toxic and becomes effective August 2018?
#65
Deoxynivalenol is a toxin produced in foods which causes foodborne illnesses associated w/cereals, wheat, and cornbread. Give the genus and species of the organism that produces this toxin.
Fusarium graminaerian
What are the three major carbohydrases?
1. a-amylases-hydrolyze a-(1,4) linkages in a random fashion. 2. b-amylases-split off maltose units from the nonreducing end. 3. Glucoamylases-split off glucose progressively from the nonreducing end.